Drawing instrument



C. A. GREEN ET AL DRAWING INSTRUMENT Filed May 23. 1921 $ept. 4, 1923.

Patented Sept. 4, 1923 1,466,712 PAT-"ENT- OFFICE.

ofialtrins A. GREEN Ann HEN Y is. sonar; or onroaeo, ILLiN'oIsnssIGNoRs To ran c. r. r'nnsn CQMPANY, or CHICAGO. rumors, aoonronnrion or ILLINOIS.

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, Application filed Ma -23,1921; seriaino; 471,672..

To all io/zomz't may concern Be it known that we, CnAnLns A. GREEN and HENRY F. Sonora, citizens of the United States, residing at Chicago, in the county'of Cook and State of Illinois, have invented certain new and useful Improvements in Drawing Instruments, of which the following is a specification. V This inventionrelates to drawing instruments, and is an improvement over the construction shown in our copending application Serial No. 417,365, filed October 16, 1920. V

In the copending application, we havedisclosed and claimed a construction for holding an inserted member, such as a needle bar, pen compass or pencil holder bar in the socket of one of the, legs of the drawing in strument, whereby the inserted member may be removed and replaced by another member when the instrument is to be used for a different purpose. In the use of a drawing instrument, it is desirable that the lower ends of the legs be arranged approximately parallel, and it has heretofore been necessary to provide a joint for connecting the detachable member to the leg and a second joint to permit the lower end of the inserted member to be arranged parallel to the lower end of the other leg. p

In our said copending application, we have provided an improvement whereby a single joint is employed for fastening the lower end of the leg in position and permitting it to be arranged substantially parallel to the lower end of the other .leg.

In the present invention, we have provided a further improvement wherein means are employed for properly centering an inserted member in the leg of the instrument. It is an object of the present invention to provide a detachable member which may be readily and quickly inserted or removed, and properly centered on the fastening element carried by the leg. It is a further ob ject to provide a single joint for securing the detachable member and permitting its adjustment parallel to the other leg of the instrument.

- In the accompanying drawings, we.have

shown one embodiment of the invention. In this showing:

Figure 1 is a side elevation,

Figure 2 is an end elevation,

Figure 3 is a horizontal sectional view on line3-3 of'Figure 1, and,

Figure 4 is a detail view of one'of inserted members.

Referring to the drawings, the instrument comprises a pair of legs'l and 2 connected at their upperends by a yoke '3 having a finger piece or. handle 4. The lower end of the v each leg of the instrument is slotted longitudinally. as at 5, forming a pair of spaced Walls 6. The walls are provided with alined openings for the reception of a threaded pin or bolt 7, adapted to receivea nut 8,.for the purpose of retaining an inserted member in position. As shown, one of the walls .6 is provided with a convex surface 9, surrounding the opening, for a purpose to be described. I

' The inserted member 10, which in this instance, is shown as a needle bar, is provided with aneedle point 11, and fastening means 12 to hold the point in position. The needle point is employed merely by way of illustration, anda pen compass or pencil bar f'holder maybe si'ibsti'tuted therefor. The 0p-' per end of the inserted member is reduced, as at13. forn'iing a pair of shoulders 14:. The reduced end is adapted to bearranged in'the longitudinal sloty5. formed in the end of the leg and is provided with a transverse slot 15, forthe reception of the fastening element 7. Surrounding the inner end of the slot, there is provided a concave surface 16, adapted to'cooperate with the convex surface 9 of the wall 6. p

lVhen the instrument is to be used, the nut 8 is loosened and the reduced end 13 of the inserted member inserted in the slot 5 from one side to permit thepin 7 to enter the transverse slot 15. As the instrument is in serted, the convex surface 9 enters the concavity 16 and properly centers the inserted member with respect to the leg 1. After the inserted member has been properly centered, it may be turned about the pin 7 as an axis, to arrange it parallel to the lower end of the other leg. VWhen the inserted member has beenproperly arranged, the nut 8 may be tightened to retainit in proper position.

By way of illustration, we have shown a drawing instrument in which the invention is applied to each of the legs. In the use of ,the' construction, however, it is only necessary to permit the removal of one of the inserted members to change the instrument from a needle bar, pen compass or pencil compass to one of the other types of constructions and any suitable joint may be employed to permit one needle bar to be arranged at an angle to the leg 2 and substantially at right angles to the paper.

It is to be understood that the form of our invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size, and arrangement-of parts may be resorted to without departing from the spiritv of the invention or the scope of the subj oincd claims. 7

Having thus described our invention, we claim: V

1. An instrument of the character described comprising a'pair of pivoted legs, a needle bar mounted in the end of one of said legs, a detachable member arranged on the end of the other leg, said leg being provided with a longitudinal slot for the reception of aid member, said detachable member being provided with a transverse slot extending from one side substantially to the center, fastening means carried by said leg and adapted to enter said slot, and said detachable member and said leg being provided with cooperating means, for positioning said fastening means in said slot.

2. An instrument of the character de scribed comprising a pair of pivoted legs, a needle bar mounted in'the end of one of said legs, the end of the other leg being slotted longitudinally, a detachable member rese /12 having a reduced end, the reduced end being provided with a transverse slot extending from one side substantially to the center and being adapted to be arranged in the slot in the end of said leg, fastening means carried by said leg and entering said transverse slot, and said 'detachablemember and said le bein provided with cooperating means, for properly positioning said fastening means in said transverse slot.

An instrument of the character described comprising a pair ofpivoted legs, a needle bar mounted in the end of one of said legs, the end of the other leg being slotted longitudinally to provide a pair of spaced walls, said walls being provided with alined openings, a fastening element extending through said openings, one of the walls being provided with a convex portion adjacent said opening a detachable member adapted to be arranged in said slot, said dctachable member being provided with a transverse slot extending from one side substantially to the center and adapted to receive said fastening element, the surface of the detachable member adjacent the inner end of said slot being provided with a depression for the reception of said convex portion. a

In testimony whereof We afix our signatures in presence of two witnesses.

- CHARLES A. GREEN.

HENRY F. SCHUH. Witnesses:

C. F. PEAsE, ANNA KULLANDER. 

